The field of this invention is polyether ester amides.
The state of the art of preparing polyether ester amides may be ascertained by reference to British Pat. Nos. 1,211,118 and 1,473,972; West German Published Application No. 2,658,714 and U.S. Pat. Nos. 3,428,710; 3,489,816; 3,944,629; 3,993,709; and 4,207,410, the disclosures of which are incorporated herein.
Polyamide plastics, additives useful therein, their properties and methods of processing, machining and finishing are disclosed in the Kirk-Othmer, "Encyclopedia of Chemical Technology," 2nd Ed. (1968) Vol. 16, pp. 88-105, the disclosure of which is incorporated herein.
The preparation of polyether ester amides, also referred to as block polyamide polyether esters, is known.
The following procedures are manufacturing processes of the prior art; the polycondensation of a polyamide forming monomer, for instance lactams, omega-aminocarboxylic acids, or equivalent amounts of dicarboxylic acids and diamines with a polyether having end located amino groups in the presence of dicarboxylic acids or with a polyether having end located carboxyl groups in the presence of diamines; and polycondensation of a polyether with polyamide oligomers including either carboxyl end groups or amine end groups. These prior art processes are disclosed in West German Published Application No. 2,658,714; British Pat. Nos. 1,211,118 and 1,473,972 and U.S. Pat. Nos. 3,428,710; 3,489,816 and 4,207,410.
It is known that polyethers and polyamides are mutually incompatible. Due to the heterogeneity of the reaction components, polycondensation takes place very slowly. Furthermore, only molded materials having a high extract content and relatively low molecular weights are obtained, so that inadequate stability is incurred in the molded articles made by injection molding and especially by the extrusion process. The use of the required high concentrations of catalysts causes insufficient stability with respect to hydrolysis in the molded materials.
The U.S. patent application of Salih Mumcu et al., filed July 10, 1980 and having Ser. No. 169,111 succeeds in obtaining advantageous molding materials by subjecting the polyethers and polyamides, which are present as polyamides bearing carboxyl end groups and polyethers bearing hydroxyl end groups or amino end groups, or as amino end-group bearing polyamides and carboxyl end-group bearing polyethers, to homogenization under water vapor pressure prior to the polycondensation.
Advantageously, polyamides are used which are obtained by hydrolytic polymerization in the presence of dicarboxylic acids. In the higher member lactams, the opening of the lactam rings under water vapor pressure of 15 to 20 bars of pressure as a rule takes substantial time, generally from 8 to 12 hours.
While it is known to manufacture polyether ester amides so that the opening of the lactam rings is carried out without water vapor pressure in the presence of dicarboxylic acids and diols or oligo ether diols or oligo ether esters, the products obtained in this manner contain an excessive amount of unreacted monomer despite a long initial condensation time of up to 24 hours.
The molecular masses of these polymers made without water vapor are too low, and therefore they are not suitable for the manufacture of molded articles by the extrusion process as disclosed in the examples of West German Published Application No. 21 35 770.